Loles <lolesft@gmail.com> writes:
> What postgres process, or system, identify and delete datafiles that have
> become unassociated? The truncate operation doesn't appear to be.. the
> datafile has existed for some time after the truncate command execution
> finished.
The zero-length file is a placeholder to ensure that that relfilenode
number doesn't get re-used right away. It'll get cleaned up during
the next checkpoint.
regards, tom lane